Mixing & Performance

Key Lock

A DSP feature that holds a track's original musical key regardless of tempo changes made with the pitch fader.

Key Lock, also called Master Tempo, is a DSP feature that time-stretches audio in real time so that a track's original musical key is preserved even when the pitch fader changes playback speed. It allows tempo adjustment without causing pitch drift.

Why it matters

When matching the BPM of tracks with wide tempo gaps, the pitch shift without key lock can make audio sound unnaturally high or low and can create harmonic clashes. Key lock keeps the musical key stable for cleaner harmonic mixing.

In practice

Key lock introduces subtle time-stretch artefacts, especially above plus or minus 6 percent tempo change. For large BPM adjustments, find a closer-tempo track instead of stretching aggressively.

Harmonic Mixing for DJs

More in Mixing & Performance

Beatgrid Waveform Quantize Hot Cue Memory Cue Loop Roll Slip Mode Pitch Fader

Frequently asked questions

Key lock, sometimes called master tempo, uses DSP pitch-shifting to keep a track's musical key constant even as you move the pitch fader to change its BPM. Without it, speeding a track up raises its pitch and slowing it down lowers it, which can sound unnatural and clash with other tracks.

Yes. The pitch-correction algorithm introduces a small amount of processing artifact, especially at extreme tempo changes of more than 6 to 8 percent. Most algorithms sound clean at minor adjustments, but heavy stretching can produce a warbling or phasey quality. Keep tempo changes modest when audio fidelity is a priority.

Many DJs leave key lock on by default so that tempo tweaks for beat matching do not shift pitch. Turn it off deliberately if you want the classic vinyl effect where pitch fader movements change both speed and key, which some DJs use as a creative or transitional tool.

Hey, it's Ben Modigell 👋

Instagram
SoundCloud
Spotify

I DJ and produce as so I so — downtempo, minimal, dub house, tech house, and techno (releases on Spotify and SoundCloud, links above). Everything I write here comes from my own gigs, studio sessions, and library cleanups: the rules I follow, the failure modes I've actually hit, and the workflow I use when nobody's watching. If a technique didn't earn its place in my own sets, it doesn't make it into a tutorial.

DJingMusic ProductionTech HouseMinimal HouseDub HouseTechnoDowntempoLibrary Organization